Nineteen women aged 19-64 years (median 38) with intractable constipation were assessed by Indium-111 DTPA colonic transit scan and barium evacuation proctogram. Patients were classified as having an isolated (I) or predominant disorder of colonic transit (II), a mixed disorder of colonic transit and rectal evacuation (III), a predominant disorder of rectal evacuation (IV) or normal colorectal emptying (V). Twelve patients fell into categories I and II and were considered suitable for surgery. Three responded to further vigorous aperient therapy and nine (32-55 years, median 38) underwent subtotal colectomy with ileorectal anastomosis at the level of the sacral promontory. Two patients required re-operation for suspected anastomotic leak. One patient required readmission on two occasions for small bowel obstruction. Follow up has been 2-21 months (median 16). Eight of the nine patients no longer take oral aperients. Eight patients have a satisfactory stool frequency of 2-8 per 24 h; the other patient has an ileostomy and incapacitating postprandial abdominal pain. Abdominal pain is troublesome in two other patients. Two patients require antidiarrhoeal therapy but none experience faecal incontinence. In severely constipated patients with a proven disorder of colonic transit but normal or near normal rectal evacuation subtotal colectomy provides excellent symptomatic relief.